Waist to height ratio
Keep your waist to less than half your height. This is the NICE rule, and this works it out for you, in inches or centimetres.
Your details
Measure halfway between your lowest rib and the top of your hip bone, breathing out normally.
Your waist to height ratio
0.48
No increased health risk
- Half your height (healthy waist for you)33.0 in
- Your waist32.0 in
- 0.6 of your height39.6 in
Your waist is under half your height, which NICE describes as no increased health risk.
No tape measure?
A healthy waist for your height
Leave the waist box empty and the calculator gives the waist size to stay under for your height: half your height, with the increased risk band running to 0.6 of it.
| Height | Keep your waist under |
|---|---|
| 5 ft 0 in | 30 in (76 cm) |
| 5 ft 4 in | 32 in (81 cm) |
| 5 ft 8 in | 34 in (86 cm) |
| 6 ft 0 in | 36 in (91 cm) |
| 6 ft 4 in | 38 in (97 cm) |
The bands
What your ratio means
| Ratio | NICE says |
|---|---|
| 0.4 to 0.49 | No increased health risk |
| 0.5 to 0.59 | Increased health risk |
| 0.6 or more | High health risk |
NICE introduced this check in 2022 and kept it in NG246 in 2025 because it works the same for every height, sex and background.
The working
A worked example
A 32 in waist is 81.3 cm. 5 ft 6 in is 167.6 cm. 81.3 ÷ 167.6 = 0.48, just under the line. Same units top and bottom is all that matters: inches over inches works just as well.
No tape?
The string trick
Cut a piece of string to your height, fold it in half and wrap it round your waist. If the ends meet, your ratio is under 0.5. The British Heart Foundation suggests it, and it is surprisingly satisfying.
Read with care
What this cannot tell you
- BMI over 35NICE says the ratio is less useful at higher BMIs. Your GP can assess things another way.
- PregnancyNot useful while you are pregnant or soon after.
- ChildrenChildren grow at different rates, so ask your GP or school nurse.
Questions
Common questions
What should my waist be for my height?
Less than half your height. At 5 ft 4 in that is under 32 in, at 6 ft it is under 36 in. Leave the waist box empty to see yours.
What is a good waist to height ratio?
Under 0.5. That means your waist is less than half your height, which NICE describes as no increased health risk.
Is waist to height better than BMI?
It is better at spotting fat around the organs, which is linked to type 2 diabetes and heart disease. NICE suggests using both.
Where exactly should I measure my waist?
Halfway between the bottom of your ribs and the top of your hip bones, usually just above the belly button. Breathe out normally and keep the tape level.
Sources
Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.
If your weight is on your mind
Talk to your GP if your weight has changed a lot without trying, or if it is worrying you. If food or your body feels hard to think about, Beat has a free helpline on 0808 801 0677 (England, weekdays 3pm to 8pm).
Related
Related calculators
- BMI calculatorWork out your Body Mass Index in stone, pounds and feet.Open
- Waist to hip ratio calculatorWaist divided by hips, against the WHO cut-offs.Open
- BMI plus waist risk explainerBMI and waist size read together, using the NICE risk table.Open
- Healthy waist size calculatorYour waist against the WHO sizes: 37 in for men, 31.5 in for women.Open
- Tape measure accuracy helperAverage two or three readings and check they agree.Open